Epidemiology and Pathogen characteristics

Methicillin resistant Staphylococcus aureus MRSA has become an increasing challenge to Public Health as it continues to develop resistance to newer antibiotics. MRSA is currently thought of as a hospital acquired infection whereas community acquired methicillin resistant Staphylococcus aureus CAMRSA causes illness in persons with no known association with hospitals and healthcare facilities.

Risk Factors

Participation in sports with the potential for personal contact such as wrestling, football, basketball, etc.

Incarceration

MSM

Crowding with poor hygiene

It is important to note that risk factors associated with CA-MRSA are not well defined and infections have occurred among previously healthy persons with no identifiable factors. Said-Salim B, Mathem B, Kreiswirth BM. Community-acquired methicillin Staphylococcus aureus: an emerging pathogen. Infection Control Hospital Epidemiology (6): 451-5.

Clinical characteristics

May present as any of the following skin infections:

Boils, abscesses, furuncles, folliculitus cellulitis.

May have the appearance of a spider bite.

Cutaneous lesions 5 cm or larger in diameter are not uncommon for this infection.

Pain and erythema that seem out of proportion to the severity of the cutaneous findings.

Necrosis is a strong indicator of infection with CA-MRSA

A more extensive archive of photos may be viewed at: This is MRSA (Methicillin-Resistant Staphylococcus aureus) (March 15, 2004)

Other presentations

With progression contiguous bone infection may occur

Necrotizing pneumonia both children and adults

Bacteremia

Although few cases are life threatening, death has been reported

Diagnosis

Incision & drainage (I&D) of the abscess. Culture the contents of the abscess.

If I&D is not performed consider culture of draining wounds or aspirate or biopsy of central area of inflammation.

Culture exudates from infected site for positive identification of the organism and antibiotic susceptibilities.

Most CA-MRSA strains are resistant to erythromycin. In the laboratory, CA-MRSA erythromycin-sensitive strains sometimes exhibit inducible resistance to Clindamycin, but this agent continues to work well in most clinical situations. Most CA-MRSA isolates remain susceptible to ciprofloxacin, but data are limited for other fluoroquinolones. More than 95% of CA-MRSA isolates are sensitive to Trimethoprim-sulfamethoxazole (TMP-SMX)

Treatment for outpatient CA-MRSA

Expert consensus recommendations are not yet available; these are interim guidelines only

If artificial nails or fingernail polish in use advise pt that treatment success improves without these present

Scrub fingernails for one minute with nail brush twice daily

Keep wounds that are draining or have exudates covered with clean dry bandages. Bandages or tape can be discarded with the regular trash.

Patient family and others in close contact should wash their hands frequently with soap and warm water or use an alcohol-based hand sanitizer, especially after changing soiled bandages or touching the infected wound.

Avoid sharing personal items such as towels, washcloths, razors, clothing or uniforms that may have had contact with the infected wound or bandage. Wash sheets, towels and clothes that become soiled with hot water (>160 F for at least 25") and laundry detergent. Dry clothes in a hot dryer.

Disinfect all non-clothing (and non-disposable items that come in contact with the wound or wound drainage) with a solution of 1 tablespoon of household bleach mixed in one quart of water prepared fresh each day or a store bought household disinfectant

Avoid participating in contact sports or other skin-to-skin activities until the infection has healed.

The Los Angeles County Department of Health Services has developed strategies for reducing transmission of CAMRSA in Non-Healthcare Settings this guide may be accessed at http://lapublichealth.org/acd/MRSA.htm

Eradication of MRSA colonization (decolonization)

There is no consensus regarding treatment to eradicate MRSA colonization. In general, decolonization is not routinely recommended*

Circumstances in which it may seem prudent to consider decolonization are:

Patients with recurrent MRSA infections despite appropriate treatment

Ongoing MRSA transmission in a well-defined cohort with ongoing contact

Additional Clinician information about MRSA is available at:

Washington State Department of Health MRSA site - Information and guidelines available
Interim Guidelines for Evaluation & Management of community Associated Methicillin Resistant staphylococcus aureus Skin and Infections in Outpatient Setting

Acknowledgements

Special thanks to Los Angeles County Department of Health Services and Washington State Department of Health for much of the information contained in this website.

﻿Physicians who need to report a suspected public health emergency should contact the Public Health division immediately at 925-313-6740; or after hours, call the sheriff's dispatch at 925-646-2441 and ask for the Health Officer On Call.